I found this picture at Flicker labeled Helio with Garrett turbine I just looked at the thumbnail and sent off a post to a friend asking what he thought it was since it didn't really look like a Helio. He of course expanded the thumbnail saw it had an N registry looked it up saw it was a DeHaviland beaver c/n 1207. Then googled the registry and came up with this kind of interesting link with some info and better picture. I really don't think it is a one of a kind anymore though.

Headed to Alaska? You can soon catch a glimpse of U.S. Fish and Wildlife Service history at the Ted Stevens Anchorage International Airport.

The above plane (N754), a testament to human ingenuity, is being installed at the airport and should be ready for its close-up in mid-November.

N754 started out as an ordinary deHavilland Beaver built in 1952, and it flew military missions in Cuba. Its transformation into something extraordinary began when the Service acquired it as surplus in 1964.